Cellulase enzymes and protease enzymes are known components of laundry detergent compositions which chemically decompose stains and provide improved cleaning of washed fabrics. For example, U.S. Pat. No. 5,858,948 describes laundry detergent compositions wherein the combination of a protease enzyme with a modified polyamine cotton soil release agent provides improved cleaning and soil release benefits.
In U.S. Pat. No. 5,707,950 the inclusion of lipase enzyme in combination with a proteolytic enzyme and a surfactant is said to provide dingy soil clean-up and whiteness maintenance benefits. The protease enzymes are described as providing from 0.005 to 0.1 Anson units of activity per gram of composition.
In U.S. Statutory Invention Registration H1513 there is described a detergent composition containing a defined fatty acid amide surfactant in combination with oleoyl sarcosinate to provide improved soil and stain removal from fabrics. Enzymes selected from among protease, cellulase and lipase enzymes are optional additives to the detergent composition to remove protein-based, carbohydrate-based or triglyceride-based stains, as well as for preventing dye transfer, and for fabric restoration.
Endo-type alkaline cellulases are a known class of cellulase enzyme which may be included as an ingredient in detergent compositions. Japanese Patent Abstracts corresponding to JP 402255898A (Oct. 16, 1990) and JP 3612802760A (Dec. 10, 1986) filed in the name of Kao Corp. describe a bacterial strain capable of producing endo-type alkaline cellulase enzymes for use in detergent compositions.
U.S. Pat. No. 5,798,327 relates to an aqueous liquid detergent composition containing a defined endoglucanase cellulase enzyme and a proteolytic enzyme. The resulting enzymatic detergent composition is said to provide in-wash stability of the cellulase enzyme.
While laundry detergent compositions containing protease, cellulase and/or lipase enzymes have been extensively described in the patent literature, there remains a need in the art for improving and enhancing the whitening and stain removal benefits capable of being provided to fabrics laundered with commercial detergent compositions containing enzymes for purposes of stain removal.